1. Field of the Invention
The present invention relates to an apparatus for chemically toughening glass and a method of chemically toughening glass using the same, and more particularly, to an apparatus for chemically toughening glass which can toughen the surface of the glass by inducing compressive stress on the glass surface through ion exchange and a method using the same.
2. Description of Related Art
The use of glass materials is soaring in a variety of industrial fields, for example, covers for photovoltaic cells or flat panel displays such as thin-film-transistor liquid crystal displays (TFT-LCDs), plasma display panels (PDPs) and organic electroluminescent (OEL) devices, as well as covers for a variety of mobile electronics. Accordingly, glass materials are required to have a light and thin profile.
However, the light and thin profile of glass materials leads to a reliability problem due to the brittleness of glass. Therefore, studies on a variety of strengthening methods are being carried out in order to realize the reliability of glass.
Glass strengthening methods typically include thermal strengthening (tempering) and chemical toughening (toughening).
Thermal strengthening is the method of strengthening a piece of glass by inducing compressive stress to the surface of the glass by heating the glass surface to a high temperature followed by rapid cooling. However, thermal strengthening has a problem in that heat is not uniformly transmitted over the entire area of the glass due to rapid cooling of the glass, thereby causing the strength of the strengthened glass to be locally non-uniform. In addition, after strengthening, the degree of curvature and light transmittance of the glass is decreased, and the refractive index becomes non-uniform. Furthermore, thermal strengthening also has the problem of inapplicability to laminated glass having a thickness of 2.5 mm or less.
Chemical toughening is the method of toughening a piece of glass by inducing compressive stress to the surface of the glass by exchanging alkali ions having a small ion radius (in general, Na ions) that are present inside the glass with alkali ions having a greater ion radius (in general, K ions). Such chemical toughening is the method that can be usefully applied to a piece of glass having a complicated shape or laminated glass having a thickness of 2 mm or less.
However, such chemical toughening is not practically applied to mass-production processes due to the problems of ion exchange efficiency, ion exchange time, toughening cost, and the like.
The information disclosed in the Background of the Invention section is provided only for better understanding of the background of the invention, and should not be taken as an acknowledgment or any form of suggestion that this information forms a prior art that would already be known to a person skilled in the art.